The invention relates to a display screen, in particular a flat display screen, comprising a glass face plate with a transparent electrode layer of a metal oxide, for example indium-doped tin oxide (ITO), and a phosphor layer.
In the case of conventional display screens, the inner surface of the glass face plate is coated with one or more structured phosphor layers, which each contain a phosphor in accordance with a dot or stripe pattern. In the case of color display screens, the pattern is formed by triplets of vertical stripes or triangularly arranged dots. Said triplets each comprise phosphor dots, which each emit one of the three primary colors red, blue and green. These phosphor layers are provided by means of a photolithographic process. They are coated with a thin aluminium layer, which serves to remove the exciting electrons.
In the case of flat display screens, use is often made of a construction principle which replaces the aluminium layer by a transparent electrode layer, which is provided on the glass face plate and on which the phosphor layers are situated. The transparent electrode layer generally consists of a transparent, electroconductive layer of indium-doped tin oxide (ITO) or other metal oxides, having a thickness of several nm to several .mu.m.
In conventional display screens, the glass surface is pre-treated in order to obtain a firm connection with sufficient adhesive strength between the glass surface of the face plate and the phosphor layers. This pre-treatment generally comprises two process steps. In a first process step, the glass surface is etched with diluted hydrofluoric acid to clean said surface and to obtain surface-active, adhesive groups, such as silanol groups (--Si--OH) or siloxane groups (--Si--O--Si--). In a second process step, a so-called pre-coating is provided which is composed of a diluted polyvinyl-alcohol solution.
In the case of ITO-coated glass surfaces, such a pre-treatment does not have the desired effect because, unlike silicon oxide, tin oxide does not form adhesive, surface-active groups. The same applies to coatings of other metal oxides which do not form adhesive, surface-active groups.
In DE-A-3600630 a description is given of a method of manufacturing a conventional display screen, in which first a PVA-containing adhesive coating is applied to the glass face plate, whereafter, following a photoprinting process, the phosphor screens are provided on the adhesive coating, said adhesive coating being provided by means of an aqueous solution containing, approximately 0.05 to 1.5 wt. %, in particular 0.08 to 0.8 wt. % polyvinyl alcohol and approximately 0.1 to 2 wt. %, in particular 0.5 to 1.5 wt. % silica sol. However, this process relates to conventional display screens which do not comprise a transparent electrode layer of indium-doped tin oxide or another metal oxide.